R mehalick



Nov. 8, 1960 J. R. MEHALICK 2,959,036

AIR CONDITIONING APPARATUS Filed Sept. 22, 1958 2 Sheets-Sheet 1 INVENTOR. w" WMM FIGJ Nov. 8, 1960 J. R. MEHALICK 2,959,036

AIR CONDITIONING APPARATUS Filed Sept. 22, 1958 2 Sheets-Sheet 2 nun g nun m m nun FIG ,3

INVENTOR. WW ##W 2,959,036 AIR CONDITIONlNG APPARATUS- John Richard Mehalick, Fayetteville, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Sept. 22, 1958, Ser. No. 762,317

6 Claims. (Cl. 62-427) This invention relates to air conditioning, more particularly to air conditioning units and to means for introducing ventilation air from the ambiance through said units.

Self-contained air conditioning units have been evolved for use in controlling air conditions in a given area. These units are generally employed for cooling the air in a conditioned area to thereby lower its temperature and/or its humidity. However, heating may also be provided by these units. Cooling operation will be here referred to, but it will be understood that the instant invention may also be applied to apparatusemployed for heating purposes. This apparatus comprises a casing separated by a partition into a condenser chamber and an evaporator chamber. Within the casing, a refrigeration system comprising a compressor, evaporator, and condenser, all arranged in a closed fluid circuit through which refrigerant may be passed, is provided. The compressor and heat dissipating condenser are arranged on the condenser chamber side of the partition and the evaporator is arranged in the evaporator chamber. In use, the air conditioning unit is installed in a window or a like wall opening with the partition serving to separate the ambiance from the conditioned area. Fans in the condenser chamber and evaporator chamber serve to set up an air stream from the ambiance and the conditioned area respectively, through said chambers. Where used, it is generally contemplated that there will be sufficient leakage into the conditioned area to provide desired amounts of fresh air for ventilation, since the conventional unit employs a so-called recirculation system whereby for cooling operation only air from the conditioned area is passed over the cooling evaporator coils. This is done to minimize the loss of cooling elfects resulting from the admission of ambient air to the conditioned area. The need has, however, arisen for the admission of ventilation air from the ambiance to dissipate smoke, cooking, and like foul odors which may accumulate in the conditioned area. Additionally, the conventional sealed installation of the unit requires that an interchange of air between the conditioned area and the ambiance be provided for when the refrigeration system of the unit is not used, as during the comfortable seasons. To this end, appropriate dampered openings have been provided in the partition to permit the selective admission of outside air through the panel. However, where ventilation air is admitted during operation of the refrigeration system of the unit, the efficiency with which the desired temperature conditions may be attained in the conditioned area is substantially diminished since the ambient air has a greater temperature differential from the air in the conditioned area than the recirculated air. Another problem arising in connection with the conventional air conditioning unit centers about the construction of the heat exchange coilsboth condenser and evaporator-em ployed in these units. The conventional heat exchanger construction employs a series of parallel runs of tubing connected by return bends, and with the effective heat transfer surface of said tubing extended by means of fins nited States PatentfO her of the unit.

produced by the refrigerant flowing through said return bends is substantially lost.

It is with the above problem in mind that the present means have been evolved, means providing for'the efiicient admission of ventilation air from the ambiance through an air conditioning unit to the conditioned area with said ventilation air being pre-treated to bring same more nearly to the temperature level within the conditioned area, so that upon subsequent passage of said ventilation air into heat exchange relationship'with the cooling evaporator coils of the unit the effectiveness of operation of the unit will not be diminished. The pretreatment of the ventilation air is accomplished byemploying the return bends of the cooling coil whereby effective use is made of these return bends for heat transfer purposes.

It is accordingly a primary object of this invention to provide an improved air conditioning unit.

Another object of the invention is to provide an air conditioning unit with improved means for the admission of ventilation air through said unit to the conditioned area. I i

A further object of the invention is to provide a novel method for the admission of ventilation air through an air conditioning unit, whereby the ventilation air will be pre-cooled prior to passage to the conditioned area.

It is also an object of this invention to provide a novel method for the admission of ventilation air through an air conditioning unit whereby the heat transfer effects of a normally unused portion of the evaporator coil may be utilized. g

A further object of the invention is to effectively employ the normally unused return bends of the heat exchangers employed in air conditioning units.

Another object of the invention is to provide an improved ventilation air guide means for directing air from the ambiance through an air conditioning unit.

An additional object of the invention is to provide improved ventilation air guide means permitting the utilization of the return bends of the evaporator coil for pre-cooling of the ventilation air.

These and other objects of the invention, which will become apparent in the following description and claims are attained by provision of novel ventilation air guide means arranged .in combination with the partition of an air conditioning unit to direct the flow of air from the ambiance, through said panel to the evaporator cham- The ventilation air guide means includes a novel duct, arranged so as to direct said ventilation air into heat exchange relationship with a return bend of the evaporator coil, whereby pre-cooling of the ventilation air will be effected. After passage of the ventilation air into heat exchange relationship with the return bend of the evaporator coil, the ventilation air is directed by means of a bafile to the evaporator chamber for cooling by the evaporator coils.

A primary feature of the invention resides in the novel ventilation air duct formed with a heat exchange portion will be made most manifest in full, clear, concise, and exact terms in conjunction with the accompanying drawings, wherein:

.Fig. 1 representsa perspective view of .an air conditioning unit .havingits top coverremoved, ,and parts broken away to reveal thestructural details ;of 1hein- .stant invention; and

.Fig. 2 is a cross-sectional view'takenconline 2-72 of Fig. 1 illustrating the details of .the novel.ventilation,air

.duct; and

'Fig. 3 is a cross-sectional view takenonline 3-3 of "Fig. 1 illustrating a detailofthe ventilation .air chamber on the condenser sideuof the partition chamber, and

comprises a base pan 11 on which aresupportedarefrigeration system including a compressor 12, a condenser 13, and an evaporator 14, connected by an appropriate refrigerant conduit (not shown). Evaporator 14 .is formed of a plurality of parallel runslof tubing15 connected by return bends 16. Two horizontally spaced vertical banks .of tubing .are here illustrated. Fin plates 17"are provided on the linear runs or bothbanksuof tubing so as to extend the effective heattransfer: surface "of said tubing.

Partition 20 is supported on base pan 11 and separates the condenser 13, and compressorlZ, from the evaporator 14. The partition 20 as seen in the drawing is formed with an offset 21 to accommodate compressor 12 and an offset22 upon which fan motor 24 issupported. Fan motor 23 drives a centrifugal evaporator fan 25 and a propeller-type condenser fan 25. Slinger ring 26 is supported on the tips of the'blades of condenser fan '25 in a suitable fashion. Condenser faniscroll 30 is sup ported on the partition'panel 20 along with evaporator fan scroll 31 as best seen in Fig. 2.

In the illustrated embodiment of the invention the air conditioning unit 10 to which the novel inventive concept is applied, employsa draw-through type condenser fan-coil assembly in which scroll 30 surrounds fan 25. The scroll 30 is formed with an outlet port 35 having .a

"damper door 36 pivotallysecured thereover. .An .appropriate control (not shown) is provided foradjusting the opening of damper door 36 over outlet 'port 35. Ventilation air chamber 37 is closed on at one end (to the right as viewed in Fig. 2) and leads to an opening 38 in partition 20. Flanges 39 extend from the condenser side of partition 20 through opening 38 for a purpose to become hereinafter more apparent.

Adapted for positioning .in assembled'relationship, 'by means of said flanges 39, are ventilation" air guide means .including a ventilation air duct 40 as best seen in Figs.

1, 2 and 4. The ventilation duct 40 comprises a leg portion 41 and a flange engaging portion 42 atits free end, va heat exchange portion 43 at its other end along with a discharge outlet 44. Heat exhcange portion 43 :is

-formed with a rectangular return bend receiving orifice 45 through which return bend 16 may extend as, seen .in

'Figs. 1 and 2.

A bafile plate 46 as best seen in Fig.2 is provided for ,.positioning over the discharge outlet of discharge portion 44 of the ventilation air duct 40, as best seen in Fig. 2.

In the preferred embodimentof the .invention bafile 46 Operation The novel inventive concept has here been disclosed as embodied in an air conditioning unit designed for cooling operation. Where the inventive concept is applied to such a unit, the unit is generally installed in a window or the like wall opening with the evaporator coil 14 oriented to face the conditioned area and the condenser coil 13 facingoutwardly to the ambiance.

In this lorientation upon initiation of operation of the :unit,:compressor 1-2 pumps.refrigerantthrough the condenser coils 13, from which it is passed to evaporator coils 14 and thence returned to the compressor 12, the refrigerant undergoing "the conventional-expansion and compression of a compression refrigeration cycle. Fan motor 23 drives the evaporator fan 24 which sets up circulation of an air stream between the conditioned area through intake louvres 47 through the filter 50 into heat exchange relationship with the evaporator coil 14 and thence outwardly through discharge louvres 48 to return to the conditioned area. On the opposite side of partition 20 condenser fan.25 draws air in from the ambiance into heatexchange relationship with condenser coils 13 and thence outwardly to the ambiance. In the illustrated embodiment the condenser fan 25 draws 'air into scroll 30. The scroll members associated with each fan maintain separation of the incoming and outgoing -air stream in the conventional manner.

Where it is'desired to introduce ventilation air into the conditioned 'area to eliminate foulodors, or staleness, of theairin the conditioned area, vent damper 36 is opened by'approprate'controls (not shown), in which case air under the influence of fan 26 in scroll 30 will "be directed into the ventilation air chamber 37, in the direction of the arrows shown in Fig. l. Thence the ventilation air moves through ventilation duct 40 where it passes 'over the return'bends 16 of the evaporator coil permitting heat exchange between the surface of these return bends 16 and the ventilation air stream. This 40 ventilation air stream is .then 're-directed by bafiie 45 into the intake air stream, passing from the conditioned area into heat exchange, relationship with the evaporator 14 for cooling thereby.

It will thus be observed that novel means have been provided for bringing in ventilation air from the ambiance cooling or heating when it is desired to bring in ventilation air for admixture with the -air in the conditioned area.

.The above disclosure has been given by way of illustration and elucidation and not by way of limitation, and it is desired to protect all embodiments of the herein disclosed inventive concept within the scope of the appended. claims.

.I claim:

.1..In an air conditioning unit. including a casinghaving .a partition definingxa condenser chamber and an evaporator chamber; a refrigeration system in said casing including an evaporator in saidevaporator chamber and a condenserin said condenser chamber; an evaporator fan .for drawing air from. a first source to be supplied with conditioned air into the evaporator chamber, into contact with said evaporator .to coolvthe .air, said fan being operative to :discharge the ,cooled airyto thetfirst. source; "and; a .fan ,for directing air from: at sec- 0nd source, separate from the source being cooled, over the condenser to dissipate the heat of condensation; ventilation means operative to supply air from said second source to the first source, said ventilation means in cludlng a duct, having a first end in communication with the second source of air and a second end in communication with the air flowing into the evaporator chamber, said duct having an opening for accommodating a portion of said evaporator for the purpose of precooling the air from said second source.

2. In an air conditioning unit including a casing having an evaporator chamber and a condenser chamber, an evaporator positioned in said evaporator chamber, a condenser positioned in said condenser chamber, said evaporator including a plurality of parallel runs connected by a plurality of return bends to form a generally serpentine coil, an evaporator fan to draw air into said evaporator chamber into contact with said evaporator to cool the air and to discharge cooled air from the unit, a condenser fan to draw air into said condenser chamber into contact with said condenser, means for introducing air from a source different from the source of air subject to the action of the evaporator fan into the air being drawn into the evaporator chamber, said means including a duct having communication with the source of air and with the air stream being drawn into the evaporator, said duct having an opening receiving a portion of the return bends therein to provide heat transfer between air flowing in'said duct and the evaporator to cool the air flowing in the duct.

3. In an air conditioner employing a heat transfer element formed of parallel runs of tubing connected by return bends, only the parallel runs being normally utilized to effect heat changes in the air of the conditioned area, means for utilizing the normally unused return bends to effect heat changes in the air of the conditioned area, said means comprising an air duct leading air to the conditioned area arranged in proximity to the heat transfer element, said duct having means admitting the return bends into the air stream passing through said duct; means for passing air through the duct whereby the air in said duct will be placed into heat exchange relationship with the return bends of the heat transfer element to utilize same; a discharge portion on said air duct; and a baffle adjacent the end of said duct redirecting the air discharged therefrom against the parallel runs of the heat transfer element.

4. For use in an air conditioning unit employing a heat transfer element formed of parallel runs of tubing connected by return bends, a partition panel separating the heat transfer element and the conditioned area from the ambiance and means supplying ventilation air into the unit from the ambiance, ventilation air guide means for guiding the air from the ambiance to the conditioned area, said guide means comprising an air duct having one end in communication with an opening in the partition panel, a discharge outlet leading to the conditioned area and a heat exchange portion in said duct in proximity to the return bends of the heat transfer element, said heat exchange portion having a return bend receiving orifice through which a return bend of the heat transfer element extends, whereby heat exchange will be effected between the air in the duct and the return bends of the heat transfer element.

5 In an air conditioning unit including a casing having an evaporator chamber and a condenser chamber, an evaporator positioned in said evaporator chamber, a com denser positioned in said condenser chamber, said evaporator including a plurality of parallel runs connected by a plurality of return bends to form a generally serpentine coil, an evaporator fan to draw air into said evaporater chamber into contact with said evaporator to cool the air and to discharge cooled air from the unit, a condenser fan to move air into said condenser chamber into contact with said condenser, means for introducing air from a source diiferent from the source of air subject to the action of the evaporator fan into the air being drawn into the evaporator chamber, said means including a duct having communication with the source of air and with the air stream being drawn into the evaporator, said air flowing in said duct being a portion of the air flowing from the discharge of the condenser fan, said duct having an opening for receiving a portion of the return bends therein to provide heat transfer between air flowing in said duct and the evaporator to cool the air flowing in the duct.

6. In an air conditioning unit including a casing 'having a partition defining a condenser chamber and an evaporator chamber; a refrigeration system in said casing including an evaporator in said evaporator chamber and a condenser in said condenser chamber, said evaporator having a plurality of substantially parallel runs connected by return bends to form a serpentine coil; an evaporator fan for drawing air from a first source to be supplied with conditioned air into the evaporator chamber, said air passing into contact with said evaporator to cool the air, said fan being operative to discharge the cool air to said first source; a fan scroll in said condenser chamber; a fan in said scroll for directing air from a second source separate from the first source over the condenser to dissipate the heat of condensation, said scroll having a port therein; means for selectively opening and closing said port, ventilation means operative to supply air from said second source to the first source, said ventilation means including a duct having a first end in communication with said port in the fan scroll and a second end in communication with the air flowing into the evaporator chamber, said duct having an opening therein, a portion of said evaporator extending through said opening into said duct to precool the flowing through said duct from the condenser chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,870,460 Lambert Aug. 9, 1932 2,140,305 Ashley Dec. 13, 1938 2,293,718 Eberhart Aug. 25, 1942 2,323,176 Ashley June 29, 1943 2,604,763 Lipman July 27, 1952 2,711,086 Eilers June 21, 1955 2,824,429 Zucker Feb. 25, 1958 

